1. Technical Field
The present invention relates to an electronic device, a manufacturing method thereof, and an electronic apparatus.
2. Related Art
Recently, electronic devices such as inertial sensors that detect physical quantities, for example, using a silicon micro electro mechanical system (MEMS) technique have been developed. Among such inertial sensors, a gyro sensor (angular velocity sensor) that detects angular velocity is used for a hand shaking correcting function of a digital camera (DSC), a motion sensing function of a game machine, and the like.
Generally, it is preferable that a vibration-type gyro sensor that vibrates a structure body and detects the Coriolis force is sealed in a vacuum environment. The reason for this is that the vibration-type gyro sensor constantly vibrates so as to detect the Coriolis force, and, in a case where air (or any other gas or the like) is present inside a package (cavity) that houses the vibration-type gyro sensor, the vibration phenomenon attenuates due to the air viscosity.
As examples of a technique for vacuum sealing the inside of the package, there is a technique using laser beams disclosed in JP-A-2005-64024 and the like. More specifically, in the technique disclosed in JP-A-2005-64024, a sphere-shaped sealing member is arranged inside a through hole of an upper package lid that is formed from silicon, and the inside of the through hole is filled by melting the sealing member using laser beams so as to vacuum-seal the inside of the package.
The silicon substrate, for example, can be processed more finely than a ceramics substrate or a crystal substrate, and can be appropriately used when a package that houses a functional element such as an inertial sensor is miniaturized. However, for example, in a case where a sealing member is arranged in a through hole (hole portion) of a package that is formed by processing a silicon substrate, and the sealing member is melted so as to close the through hole, there is a case where cracks occur on the periphery of the through hole in the package. Such cracks occur markedly in a case where a silicon substrate is used. When a package in which cracks occur is used, there are cases where the reliability of the electronic device whose package houses a functional element is degraded.